1. Field of the Invention
The present invention relates to a method of manufacturing sliders, a method of manufacturing slider materials, and slider materials that are used for manufacturing sliders for thin-film magnetic head""s, for example.
2. Description of the Related Art
A flying-type thin-film magnetic head used for a magnetic disk device and so on is generally made up of a thin-film magnetic head slider (that may be simply called a slider) having a thin-film magnetic head element provided at the trailing edge of the slider. The slider generally comprises a rail whose surface functions as a medium facing surface (an air bearing surface) and a tapered section or a step near the end on the air inflow side. The rail flies slightly above the surface of a recording medium such as a magnetic disk by means of air flow from the tapered section or step.
A thin-film magnetic head element generally used is a composite-type element made up of layers of an induction magnetic transducer for writing and a magnetoresistive (MR) element for reading.
In general, such thin-film magnetic head sliders are formed through cutting a wafer in one direction in which sections to be sliders (called slider sections in the following description) each including a thin-film magnetic head element are arranged in a plurality of rows. A block called a bar in which the slider sections are arranged in a row is thereby formed. Rails are then formed in the bar and the bar is cut into the sliders.
The manufacturing process of the sliders includes a step of processing a surface to be the medium facing surface (hereinafter called the medium facing surface for convenience) of the bar, that is, grinding or lapping the medium facing surface and a step of cutting the wafer into the bars. The order of the step of processing the medium facing surface and the step of cutting the wafer into the bars depends on methods of processing the medium facing surface and cutting the wafer, as described later.
In the step of processing the medium facing surface, it is required that the MR height and the throat height of each thin-film magnetic head element formed in the bar fall within a tolerance range and that processing accuracy of the surface processed fall within a tolerance range. The MR height is the length (height) between an end of the MR element close to the medium facing surface and the other end. The throat height is the length (height) of the magnetic pole of an induction magnetic transducer between an end close to the medium facing surface and the other end.
In prior art the following method is generally taken to process the medium facing surfaces of bars and cutting a wafer into the bars. That is, a bar including a row of slider sections is cut from a wafer. The bar is fixed to a specific jig by bonding the surface of the bar opposite to the medium facing surface to the jig. The medium facing surface of the bar thus fixed to the jig is then processed. This method is called a first method in the following description. The first method is disclosed in, for example, Published Unexamined Japanese Patent Application Hei 10-228617 (1998), Published Unexamined Japanese Patent Application Hei 8-315341 (1996), and Published Unexamined Japanese Patent Application Hei 9-274714 (1997).
In prior art, second to sixth methods described below have been proposed, in addition to the above-described first method, for processing the medium facing surfaces of bars and cutting a wafer into the bars.
The second method is, as shown in FIG. 7 of U.S. Pat. No. 5,406,694, for example, a specific length of block including rows of slider sections is cut from a wafer. The block is fixed to a specific jig by bonding the surface of the block opposite to the medium facing surface to the jig. The medium facing surface of the block thus fixed to the jig is then processed. The block is then cut into bars whose medium facing surfaces have been processed.
The third method is, as shown in FIG. 3 of Published Unexamined Japanese Patent Application Hei 4-289511 (1992), for example, a wafer is fixed to a specific jig and the medium facing surface of the wafer fixed to the jig is processed. The wafer is then cut into bars whose medium facing surfaces have been processed.
The fourth method is, as shown in FIG. 7 of Published Unexamined Japanese Patent Application Hei 4-289511, for example, a wafer or a block having a specific length and including rows of slider sections cut from a wafer is utilized. A reference surface opposite to the medium facing surface of the wafer or block is processed. The wafer or block is then fixed to a specific jig by bonding the reference surface to the jig. The wafer or block is cut at a position to be the medium facing surface. A bar is thus separated while fixed to the jig and the medium facing surface of the bar is processed.
The fifth method is, as shown in FIG. 8 and FIG. 9 of Published Unexamined Japanese Patent Application Laid-open Hei 4-289511, for example, a wafer utilized has slider sections formed such that medium facing surfaces of adjacent rows face each other or surfaces opposite to the medium facing surfaces of adjacent rows face each other. The wafer is cut at a position where the surfaces opposite to the medium facing surfaces face each other to obtain a block including two rows of slider sections. A specific jig is fixed to each end face of the block through the use of an adhesive. The block is then cut at a position where the medium facing surfaces face each other to separate the block into two bars each fixed to the jig. The medium facing surface of each bar is then processed.
The sixth method is, as shown in FIG. 10 and FIG. 11 of Published Unexamined Japanese Patent Application Hei 4-289511, for example, a wafer utilized has slider sections formed such that medium facing surfaces of adjacent rows face each other or surfaces opposite to the medium facing surfaces of adjacent rows face each other. The wafer is cut at a position where the medium facing surfaces face each other to obtain a block including two rows of slider sections. A specific jig is fixed to one medium facing surface of the block through the use of an adhesive. The other medium facing surface of the block is then processed. A specific jig is fixed to the other medium facing surface thus processed through the use of an adhesive. The jig is detached from the one medium facing surface and this medium facing surface is processed. The block is cut at a position where the surfaces opposite to the medium facing surfaces face each other to separate the block into two bars.
Of the foregoing methods, in the first method the bar including a row of slider sections is cut from the wafer. The bar is fixed to the jig and the medium facing surface of the separated bar is then processed. Consequently, the bar is often affected by the state of the interface between the bar and the jig or by warpage caused by bonding and likely to be deformed and to form a curvature and the like. As a result, it is likely that processing accuracy of the surface of the bar processed is reduced and deformation occurs, such as curvatures of the layers (pattern) making up the thin-film magnetic head elements formed in the bar. In addition, it is difficult to precisely control the resistance of the MR element, the MR height and the throat height. It is therefore difficult to precisely fabricate thin-film magnetic head sliders with excellent properties.
In the fifth and sixth methods, the block including two rows of slider sections is cut from the wafer and the block is fixed to the jig. In this case, too, problems similar to those of the first method described above may result since the block is thin and easy to deform. Furthermore, in the fifth and sixth methods, in the block including two rows of slider sections, the thin-film magnetic head elements in one of the rows are opposite in direction to the head elements in the other row. As a result, the number of steps required for processing the medium facing surface and separating the bar increases.
In contrast, the second to fourth methods do not include the step of fixing a separate bar or block including two rows of slider sections cut off from a wafer to the jig. Therefore, the above-stated problems are reduced.
However, in the third and fourth methods, every time a bar is separated, the step is required for fixing the wafer or block to the jig or detaching the bar or block from the jig. The manufacturing process is thereby complicated and the production efficiency is reduced. In the third method, the shape of the wafer as an object whose medium facing surface is processed is changed, depending on the number of rows of slider sections remaining in the wafer. Consequently, handling of the wafer is inconvenient when the medium facing surface is processed. In the fourth method, too, handling of the wafer is inconvenient when the medium facing surface is processed since the length of each bar separated varies.
In the second method, in contrast, the block utilized includes a plurality of rows of slider sections and has a specific width. The thin-film magnetic head elements in the slider sections face toward one direction. The steps of processing the medium facing surface and separating the bar are repeated. These steps are thus easily performed.
A block as the one used in the second method, for example, that includes rows of slider sections and has a specific width is obtained from a rectangular wafer without waste.
In contrast, to obtain a block having a specific width from a circular wafer, a single rectangular block 202 is obtained from a circular wafer 201 in prior art, as shown in FIG. 15.
However, when the block 202 is obtained as described above, a relatively large portion of the wafer 201 from the periphery of the block 202 to the periphery of the wafer 201 is wasted. Therefore, the number of sliders obtained from the single wafer 201 is reduced.
It is an object of the invention to provide a method of manufacturing sliders, a method of manufacturing slider materials, and slider materials for facilitating processing and increasing the number of sliders obtained as large as possible when sliders are fabricated through the use of a circular-plate-shaped wafer in which rows of sections to be sliders are arranged.
A method of the invention is provided for manufacturing slider materials. The slider materials are used for fabricating sliders having medium facing surfaces on which specific processing is performed. The slider materials each have a specific width and include a plurality of rows of sections to be the sliders aligned in one orientation. The method includes the steps of: fabricating a circular-plate-shaped wafer including the plurality of rows of the sections to be the sliders aligned in the one orientation; and forming the slider materials through cutting a plurality of types of slider materials having different widths out of the wafer.
A method of the invention is provided for manufacturing sliders having medium facing surfaces on which specific processing is performed. The method includes the steps of: fabricating a circular-plate-shaped wafer including a plurality of rows of sections to be the sliders aligned in one orientation; forming slider materials through cutting a plurality of types of the slider materials having different widths out of the wafer, the slider materials each having a specific width and including some of the rows of the sections to be the sliders aligned in the one orientation; performing the specific processing on one of the rows of the sections to be the sliders located at an end of each of the slider materials; forming a slider aggregate made up of the one of the rows of the sections to be the sliders on which the processing has been performed, through cutting each of the slider materials having gone through the processing; and forming the sliders through separating the slider aggregate.
Slider materials of the invention each have a specific width and include a plurality of rows of sections to be sliders aligned in one orientation. The slider materials are obtained through cutting a plurality of types of the slider materials having different widths out of a circular-plate-shaped wafer including the plurality of rows of the sections to be the sliders aligned in the one orientation.
According to the method of manufacturing slider materials, the method of manufacturing sliders, or the slider materials of the invention, the slider materials are formed through cutting a plurality of types of slider materials having different widths out of the circular-plate-shaped wafer. As a result, the number of the sliders obtained from the wafer is as large as possible.
In the invention one orientation means that portions to be the medium facing surfaces of the sections to be the sliders face one direction.
In the method of manufacturing slider materials, the method of manufacturing sliders, or the slider materials of the invention, a diameter of the wafer is any of 76.2 mm (3 inches), 152.4 mm (6 inches) and 203.2 mm (8 inches).
In the method of manufacturing slider materials, the method of manufacturing sliders, or the slider materials, the number of the types of the slider materials may be two. In this case, the widths of the slider materials may be two types of 69.6 mmxc2x15% and 57.6 mmxc2x15%.
In the method of manufacturing slider materials, the method of manufacturing sliders, or the slider materials, the number of the types of the slider materials may be three. In this case, the widths of the slider materials may be three types of 69.6 mmxc2x15%, 57.6 mmxc2x15%, and 38.4 mmxc2x15%.
In the method of manufacturing slider materials, the method of manufacturing sliders, or the slider materials, the slider materials may include four to ten rows of the sections to be the sliders.
In the method of manufacturing slider materials, the method of manufacturing sliders, or the slider materials, the sections to be the sliders may include thin-film magnetic head elements.
In the method of manufacturing slider materials, the method of manufacturing sliders, or the slider materials, the step of performing the specific processing may include lapping of surfaces to be the medium facing surfaces.
Other and further objects, features and advantages of the invention will appear more fully from the following description.